Tuesday, June 30, 2015

"WASHINGTON — Five months before a United Nations summit meeting aimed at forging a historic global accord to cut climate-warming emissions, significant signs of progress toward an agreement are emerging."

"BAR HARBOR, Me. — Like many residents of this picturesque island town on the edge of Acadia National Park, Zach Soares had trouble keeping his house warm, going through five cords of wood in the winter. So he jumped at an offer last year for free energy improvements through a class project at the College of the Atlantic, where he works.

"WASHINGTON — President Obama said Tuesday that he was trying to prod European leaders to salvage a deal to keep Greece in the eurozone, even as his government was bracing for the possible consequences of a once unimaginable divorce."

"ATHENS — With just hours to go before Greece hits a deadline for a debt payment it cannot afford, Prime Minister Alexis Tsipras on Tuesday asked the other nations that use the euro to extend another bailout and buy Athens time to renegotiate its crippling debt load."

NEW YORK – The rising crescendo of bickering and acrimony within Europe might seem to outsiders to be the inevitable result of the bitter endgame playing out between Greece and its creditors. In fact, European leaders are finally beginning to reveal the true nature of the ongoing debt dispute, and the answer is not pleasant: it is about power and democracy much more than money and economics.

Of course, the economics behind the program that the “troika” (the European Commission, the European Central Bank, and the International Monetary Fund) foisted on Greece five years ago has been abysmal, resulting in a 25% decline in the country’s GDP. I can think of no depression, ever, that has been so deliberate and had such catastrophic consequences: Greece’s rate of youth unemployment, for example, now exceeds 60%.

It is startling that the troika has refused to accept responsibility for any of this or admit how bad its forecasts and models have been. But what is even more surprising is that Europe’s leaders have not even learned. The troika is still demanding that Greece achieve a primary budget surplus (excluding interest payments) of 3.5% of GDP by 2018.

Economists around the world have condemned that target as punitive, because aiming for it will inevitably result in a deeper downturn. Indeed, even if Greece’s debt is restructured beyond anything imaginable, the country will remain in depression if voters there commit to the troika’s target in the snap referendum to be held this weekend.

In terms of transforming a large primary deficit into a surplus, few countries have accomplished anything like what the Greeks have achieved in the last five years. And, though the cost in terms of human suffering has been extremely high, the Greek government’s recent proposals went a long way toward meeting its creditors’ demands.

We should be clear: almost none of the huge amount of money loaned to Greece has actually gone there. It has gone to pay out private-sector creditors – including German and French banks. Greece has gotten but a pittance, but it has paid a high price to preserve these countries’ banking systems. The IMF and the other “official” creditors do not need the money that is being demanded. Under a business-as-usual scenario, the money received would most likely just be lent out again to Greece.

But, again, it’s not about the money. It’s about using “deadlines” to force Greece to knuckle under, and to accept the unacceptable – not only austerity measures, but other regressive and punitive policies.

But why would Europe do this? Why are European Union leaders resisting the referendum and refusing even to extend by a few days the June 30 deadline for Greece’s next payment to the IMF? Isn’t Europe all about democracy?

In January, Greece’s citizens voted for a government committed to ending austerity. If the government were simply fulfilling its campaign promises, it would already have rejected the proposal. But it wanted to give Greeks a chance to weigh in on this issue, so critical for their country’s future wellbeing.

That concern for popular legitimacy is incompatible with the politics of the eurozone, which was never a very democratic project. Most of its members’ governments did not seek their people’s approval to turn over their monetary sovereignty to the ECB. When Sweden’s did, Swedes said no. They understood that unemployment would rise if the country’s monetary policy were set by a central bank that focused single-mindedly on inflation (and also that there would be insufficient attention to financial stability). The economy would suffer, because the economic model underlying the eurozone was predicated on power relationships that disadvantaged workers.

And, sure enough, what we are seeing now, 16 years after the eurozone institutionalized those relationships, is the antithesis of democracy: Many European leaders want to see the end of Prime Minister Alexis Tsipras’s leftist government. After all, it is extremely inconvenient to have in Greece a government that is so opposed to the types of policies that have done so much to increase inequality in so many advanced countries, and that is so committed to curbing the unbridled power of wealth. They seem to believe that they can eventually bring down the Greek government by bullying it into accepting an agreement that contravenes its mandate.

It is hard to advise Greeks how to vote on July 5. Neither alternative – approval or rejection of the troika’s terms – will be easy, and both carry huge risks. A yes vote would mean depression almost without end. Perhaps a depleted country – one that has sold off all of its assets, and whose bright young people have emigrated – might finally get debt forgiveness; perhaps, having shriveled into a middle-income economy, Greece might finally be able to get assistance from the World Bank. All of this might happen in the next decade, or perhaps in the decade after that.

By contrast, a no vote would at least open the possibility that Greece, with its strong democratic tradition, might grasp its destiny in its own hands. Greeks might gain the opportunity to shape a future that, though perhaps not as prosperous as the past, is far more hopeful than the unconscionable torture of the present.

"It has been obvious for some time that the creation of the euro was a terrible mistake. Europe never had the preconditions for a successful single currency — above all, the kind of fiscal and banking union that, for example, ensures that when a housing bubble in Florida bursts, Washington automatically protects seniors against any threat to their medical care or their bank deposits."

Saturday, June 27, 2015

"Until now, every warning about an imminent breakup of the euro has proved wrong. Governments, whatever they said during the election, give in to the demands of the troika; meanwhile, the ECB steps in to calm the markets. This process has held the currency together, but it has also perpetuated deeply destructive austerity — don’t let a few quarters of modest growth in some debtors obscure the immense cost of five years of mass unemployment."

"BRUSSELS — Eurozone finance ministers on Saturday rejected Greece’s request to extend its debt negotiations beyond Tuesday’s deadline, seeming to bring a bitter end to months of discussions of how or whether to continue providing bailout loans to Athens."

Friday, June 26, 2015

At another incident during a presidential visit to South Carolina, protester Brett Bursey refused an order by Secret Service agents to go to a free speech zone half-a-mile away. He was arrested and charged with trespassing by the South Carolina police. "Bursey said that he asked the policeman if 'it was the content of my sign,' and he said, 'Yes, sir, it's the content of your sign that's the problem.'"[18] However, the prosecution, led by James Strom Thurmond Jr., disputes Bursey's version of events.[26] Trespassing charges against Bursey were dropped, and Bursey was instead indicted by the federal government for violation of a federal law that allows the Secret Service to restrict access to areas visited by the president.[18] Bursey faced up to six months in prison and a US$5,000 fine.[18]After a bench trial, Bursey was convicted of the offense of trespassing, but judge Bristow Marchant deemed the offense to be relatively minor and ordered a fine of $500 be assessed, which Bursey appealed, and lost.[27] In his ruling, Marchant found that "this is not to say that the Secret Service's power to restrict the area around the President is absolute, nor does the Court find that protesters are required to go to a designated demonstration area — which was an issue in this case — as long as they do not otherwise remain in a properly restricted area."[27]

Marchant's ruling however, was criticized for three reasons:

The ruling found that Bursey was not the victim of selective prosecution because Bursey was the only person who had refused an order to leave the area. However, this overlooks the fact that nobody else refused to leave the zone because nobody else was asked to leave.[28]

The prosecution claimed that the protected zone around the President was 100 yards wide. However, it was unmarked, with cars and trucks allowed to pass through and drop off ticket-holders, and nobody was willing to tell protesters where the zone's boundaries were. Marchant's decision noted this but did not find this unreasonable.[28]

Marchant found that in the "age of suicide bombers", the Secret Service should have latitude to get rid of anyone suspicious who is standing near the president's route. However, given that the reason Bursey was singled out by the Secret Service was his sign, "it's enough to make anyone with a dissenting view think twice before deciding to stand out from a crowd."[28]

Was I on the edge of my seat, waiting for the Supreme Court decision on Obamacare subsidies? No — I was pacing the room, too nervous to sit, worried that the court would use one sloppily worded sentence to deprive millions of health insurance, condemn tens of thousands to financial ruin, and send thousands to premature death.

It didn’t. And that means that the big distractions — the teething problems of the website, the objectively ludicrous but nonetheless menacing attempts at legal sabotage — are behind us, and we can focus on the reality of health reform. The Affordable Care Act is now in its second year of full operation; how’s it doing?

The answer is, better than even many supporters realize.

Start with the act’s most basic purpose, to cover the previously uninsured. Opponents of the law insisted that it would actually reduce coverage; in reality, around 15 million Americans have gained insurance.

Macroeconomics, trade, health care, social policy and politics.

But isn’t that a very partial success, with millions still uncovered? Well, many of those still uninsured are in that position because their state governments have refused to let the federal government enroll them in Medicaid.

Beyond that, you need to realize that the law was never intended or expected to cover everyone. Undocumented immigrants aren’t eligible, and any system that doesn’t enroll people automatically will see some of the population fall through the cracks. Massachusetts has had guaranteed health coverage for almost a decade, but 5 percent of its nonelderly adult population remains uninsured.

Suppose we use 5 percent uninsured as a benchmark. How much progress have we made toward getting there? In states that have implemented the act in full and expanded Medicaid, data from the Urban Institute show the uninsured falling from more than 16 percent to just 7.5 percent — that is, in year two we’re already around 80 percent of the way there. Most of the way with the A.C.A.!

But how good is that coverage? Cheaper plans under the law do have relatively large deductibles and impose significant out-of-pocket costs. Still, the plans are vastly better than no coverage at all, or the bare-bones plans that the act made illegal. The newly insured have seen a sharp drop in health-related financial distress, and report a high degree of satisfaction with their coverage.

What about costs? In 2013 there were dire warnings about a looming “rate shock”; instead, premiums came in well below expectations. In 2014 the usual suspects declared that huge premium increases were looming for 2015; the actual rise was just 2 percent. There was another flurry of scare stories about rate hikes earlier this year, but as more information comes in it looks as if premium increases for 2016 will be bigger than for this year but still modest by historical standards — which means that premiums remain much lower than expected.

And there has also been a sharp slowdown in the growth of overall health spending, which is probably due in part to the cost-control measures, largely aimed at Medicare, that were also an important part of health reform.

What about economic side effects? One of the many, many Republican votes against Obamacare involved passing something called the Repealing the Job-Killing Health Care Law Act, and opponents have consistently warned that helping Americans afford health care would lead to economic doom. But there’s no job-killing in the data: The U.S. economy has added more than 240,000 jobs a month on average since Obamacare went into effect, its biggest gains since the 1990s.

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Finally, what about claims that health reform would cause the budget deficit to explode? In reality, the deficit has continued to decline, and the Congressional Budget Office recently reaffirmed its conclusionthat repealing Obamacare would increase, not reduce, the deficit.

Put all these things together, and what you have is a portrait of policy triumph — a law that, despite everything its opponents have done to undermine it, is achieving its goals, costing less than expected, and making the lives of millions of Americans better and more secure.

Now, you might wonder why a law that works so well and does so much good is the object of so much political venom — venom that is, by the way, on full display in Justice Antonin Scalia’s dissenting opinion, with its rants against “interpretive jiggery-pokery.” But what conservatives have always feared about health reform is the possibility that it might succeed, and in so doing remind voters that sometimes government action can improve ordinary Americans’ lives.

That’s why the right went all out to destroy the Clinton health plan in 1993, and tried to do the same to the Affordable Care Act. But Obamacare has survived, it’s here, and it’s working. The great conservative nightmare has come true. And it’s a beautiful thing.

"Searing temperatures, which have been as high as 113 degrees, fell below 100 on Thursday, but a sense of panic and crisis persisted in the city, the country’s financial and commercial capital as well as the capital of Sindh Province."

Abstract

The oft-repeated claim that Earth’s biota is entering a sixth “mass extinction” depends on clearly demonstrating that current extinction rates are far above the “background” rates prevailing between the five previous mass extinctions. Earlier estimates of extinction rates have been criticized for using assumptions that might overestimate the severity of the extinction crisis. We assess, using extremely conservative assumptions, whether human activities are causing a mass extinction. First, we use a recent estimate of a background rate of 2 mammal extinctions per 10,000 species per 100 years (that is, 2 E/MSY), which is twice as high as widely used previous estimates. We then compare this rate with the current rate of mammal and vertebrate extinctions. The latter is conservatively low because listing a species as extinct requires meeting stringent criteria. Even under our assumptions, which would tend to minimize evidence of an incipient mass extinction, the average rate of vertebrate species loss over the last century is up to 100 times higher than the background rate. Under the 2 E/MSY background rate, the number of species that have gone extinct in the last century would have taken, depending on the vertebrate taxon, between 800 and 10,000 years to disappear. These estimates reveal an exceptionally rapid loss of biodiversity over the last few centuries, indicating that a sixth mass extinction is already under way. Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts, but that window of opportunity is rapidly closing.

Keywords

Sixth mass extinction

vertebrate extinctions

rates of extinction

background extinction

modern vertebrate losses

INTRODUCTION

The loss of biodiversity is one of the most critical current environmental problems, threatening valuable ecosystem services and human well-being (1–7). A growing body of evidence indicates that current species extinction rates are higher than the pre-human background rate (8–15), with hundreds of anthropogenic vertebrate extinctions documented in prehistoric and historic times (16–23). For example, in the islands of tropical Oceania, up to 1800 bird species (most described in the last few decades from subfossil remains) are estimated to have gone extinct in the ~2000 years since human colonization (24). Written records of extinctions of large mammals, birds, and reptiles date back to the 1600s and include species such as the dodo (Raphus cucullatus, extinguished in the 17th century), Steller’s sea cow (Hydrodamalis gigas, extinguished in the 18th century), and the Rodrigues giant tortoise (Cylindraspis peltastes, extinguished in the 19th century). More species extinction records date from the 19th century and include numerous species of mammals and birds. Records of extinction for reptiles, amphibians, freshwater fishes, and other organisms have mainly been documented since the beginning of the 20th century (14, 17). Moreover, even in species that are not currently threatened, the extirpation of populations is frequent and widespread, with losses that far outstrip species-level extinctions (18, 25). Population-level extinction directly threatens ecosystem services and is the prelude to species-level extinction (18).

Here, we analyze the modern rates of vertebrate species extinction and compare them with a recently computed background rate for mammals (7). We specifically addressed the following questions: (i) Are modern rates of mammal and vertebrate extinctions higher than the highest empirically derived background rates? (ii) How have modern extinction rates in mammals and vertebrates changed through time? (iii) How many years would it have taken for species that went extinct in modern times to have been lost if the background rate had prevailed? These are important issues because the uncertainties about estimates of species loss have led skeptics to question the magnitude of anthropogenic extinctions (26) and because understanding the magnitude of the extinction crisis is relevant for conservation, maintenance of ecosystem services, and public policy.

Until recently, most studies of modern extinction rates have been based on indirect estimates derived, for example, on the rates of deforestation and on species-area relationships (11, 14). Problems related to estimating extinction since 1500 AD (that is, modern extinctions) have been widely discussed, and the literature reflects broad agreement among environmental scientists that biases lead to underestimating the number of species that have gone extinct in the past few centuries—the period during which Homo sapiens truly became a major force on the biosphere (1–4, 6–8, 14, 15). However, direct evaluation is complicated by uncertainties in estimating the incidence of extinction in historical time and by methodological difficulties in comparing contemporary extinctions with past ones.

Less discussed are assumptions underlying the estimation of background extinction rates. The lower these estimates, the more dramatic current extinction rates will appear by comparison. In nearly all comparisons of modern versus background extinction rates, the background rate has been assumed to be somewhere between 0.1 and 1 species extinction per 10,000 species per 100 years (equal to 0.1 to 1 species extinction per million species per year, a widely used metric known as E/MSY). Those estimates reflect the state of knowledge available from the fossil record in the 1990s (7, 9–13). In a recent analysis, which charted the stratigraphic ranges of thousands of mammal species, extinction rates were measured over intervals ranging from single years to millions of years, and the mean extinction rate and variance were computed for each span of time (7). In this way, the background extinction rate estimated for mammals was estimated at 1.8 E/MSY, here rounded upward conservatively to 2 E/MSY (that is, 2 extinctions per 100 years per 10,000 species). This is double the highest previous rough estimate.

Those previously estimated background rates were primarily derived from marine invertebrate fossils, which are likely to have greater species longevity than vertebrates (10, 15). Data deficiencies make it impossible to conduct empirical analyses (as was done for mammals) for non-mammal terrestrial vertebrates; therefore, we assume the background rates of other vertebrates to be similar to those of mammals. This supposition leads to a more conservative assessment of differences between current and past extinction rates for the vertebrates as a whole, compared with using the very low background extinction rate derived from marine invertebrates.

The analysis we present here avoids using assumptions such as loss of species predicted from species-area relationships, which can suggest very high extinction rates, and which have raised the possibility that scientists are “alarmists” seeking to exaggerate the impact of humans on the biosphere (26). Here, we ascertain whether even the lowest estimates of the difference between background and contemporary extinction rates still justify the conclusion that people are precipitating a global spasm of biodiversity loss.

RESULTS

Modern and background rates of vertebrate extinctions

Modern rates of vertebrate extinction were much higher than a background extinction rate of 2 E/MSY. Among the vertebrate taxa evaluated by the International Union of Conservation of Nature (IUCN), 338 extinctions have been documented since 1500 [“extinct” (EX), Table 1]. An additional 279 species have become either “extinct in the wild” (EW) or listed as “possibly extinct” (PE), totaling 617 vertebrate species summed over the three categories. Most extinctions have occurred in the last 114 years (that is, since 1900; Table 1). Our estimated “highly conservative” (that is, using data for EX species only) and “conservative” (that is, by including EX, EW, and PE) modern extinction rates for vertebrates varied from 8 to 100 times higher than the background rate (Table 2). This means, for example, that under the 2 E/MSY background rate, 9 vertebrate extinctions would have been expected since 1900; however, under the conservative rate, 468 more vertebrates have gone extinct than would have if the background rate had persisted across all vertebrates under that period. Specifically, these 468 species include 69 mammal species, 80 bird species, 24 reptiles, 146 amphibians, and 158 fish.

Table 1Numbers of species used in the Table 2 calculations of “highly conservative” and “conservative” modern extinction rates based on the IUCN Red List (17).

For the highly conservative rates, only species verified as “extinct” (EX) were included; for the conservative extinction rates, species in the categories “extinct in the wild” (EW) and “possibly extinct” (PE) were also included.

Variation in modern extinction rates through time

Modern extinction rates have increased sharply over the past 200 years (corresponding to the rise of industrial society) and are considerably higher than background rates (Fig. 1). Rates of modern extinctions vary among vertebrate groups (Fig. 1). For example, amphibians, comprising of ~7300 species, show an accelerating rate of extinction: only 34 extinctions have been documented with a high level of certainty since 1500, yet >100 species have likely disappeared since 1980 (17, 23). This may not only reflect real trends but also a shortage of data for groups for which most species are not yet evaluated, such as reptiles and fish (21, 22).

Fig. 1Cumulative vertebrate species recorded as extinct or extinct in the wild by the IUCN (2012).

Graphs show the percentage of the number of species evaluated among mammals (5513; 100% of those described), birds (10,425; 100%), reptiles (4414; 44%), amphibians (6414; 88%), fishes (12,457; 38%), and all vertebrates combined (39,223; 59%). Dashed black curve represents the number of extinctions expected under a constant standard background rate of 2 E/MSY. (A) Highly conservative estimate. (B) Conservative estimate.

Modern extinctions if background rate had prevailed

Our results indicate that modern vertebrate extinctions that occurred since 1500 and 1900 AD would have taken several millennia to occur if the background rate had prevailed. The total number of vertebrate species that went extinct in the last century would have taken about 800 to 10,000 years to disappear under the background rate of 2 E/MSY (Fig. 2). The particularly high losses in the last several decades accentuate the increasing severity of the modern extinction crisis.

Fig. 2Number of years that would have been required for the observed vertebrate species extinctions in the last 114 years to occur under a background rate of 2 E/MSY.

Red markers, highly conservative scenario; blue markers, conservative scenario. Note that for all vertebrates, the observed extinctions would have taken between 800 to 10,000 years to disappear, assuming 2 E/MSY. Different classes of vertebrates all show qualitatively similar trends.

DISCUSSION

Arguably the most serious aspect of the environmental crisis is the loss of biodiversity—the other living things with which we share Earth. This affects human well-being by interfering with crucial ecosystem services such as crop pollination and water purification and by destroying humanity’s beautiful, fascinating, and culturally important living companions (4, 5, 15, 27–30).

Our analysis shows that current extinction rates vastly exceed natural average background rates, even when (i) the background rate is considered to be double previous estimates and when (ii) data on modern vertebrate extinctions are treated in the most conservative plausible way. We emphasize that our calculations very likely underestimate the severity of the extinction crisis because our aim was to place a realistic “lower bound” on humanity’s impact on biodiversity. Therefore, although biologists cannot say precisely how many species there are, or exactly how many have gone extinct in any time interval, we can confidently conclude that modern extinction rates are exceptionally high, that they are increasing, and that they suggest a mass extinction under way—the sixth of its kind in Earth’s 4.5 billion years of history.

A final important point is that we focus exclusively on species, ignoring the extirpation of populations—the units relevant to ecological functioning and the delivery of ecosystem services (4, 5, 29). Population extinction cannot be reliably assessed from the fossil record, precluding any analysis along the lines of that presented here. Also, although it is clear that there are high rates of population extinction (18), existing data are much less reliable and far harder to obtain than those for species, which will remain true for the foreseeable future. Likewise, we have not considered animals other than vertebrates because of data deficiencies.

The evidence is incontrovertible that recent extinction rates are unprecedented in human history and highly unusual in Earth’s history. Our analysis emphasizes that our global society has started to destroy species of other organisms at an accelerating rate, initiating a mass extinction episode unparalleled for 65 million years. If the currently elevated extinction pace is allowed to continue, humans will soon (in as little as three human lifetimes) be deprived of many biodiversity benefits. On human time scales, this loss would be effectively permanent because in the aftermath of past mass extinctions, the living world took hundreds of thousands to millions of years to rediversify. Avoiding a true sixth mass extinction will require rapid, greatly intensified efforts to conserve already threatened species and to alleviate pressures on their populations—notably habitat loss, overexploitation for economic gain, and climate change (31–33). All of these are related to human population size and growth, which increases consumption (especially among the rich), and economic inequity (6). However, the window of opportunity is rapidly closing.

MATERIALS AND METHODS

To estimate modern extinction rates, we compiled data on the total number of described species and the number of extinct and possibly extinct vertebrate species from the 2014 IUCN Red List (17). In the IUCN’s list, extinct species can be viewed as the minimum number of actual extinctions during recent human history (that is, since 1500) because it lists species known to be extinct (EX), extinct in the wild (EW), and possibly extinct (PE, a subcategory within “critically endangered” reserved for species thought to be extinct, but not confirmed) (17) (table S1). We used the IUCN data to calculate modern extinction rates in two ways: (i) we estimate a “highly conservative modern extinction rate” by using the data exclusively on species listed as EX, and (ii) we calculate a “conservative extinction rate” by including also both EW and PE species (table S2). Including these latter two categories recognizes that there is only a slim chance that most of the species in those categories can reestablish viable populations in their native habitats. In terms of biological impact and the provision of ecosystem services, we consider EW and PE species to be functionally equivalent to EX species: even if some individuals still exist, their abundances are not sufficient to have a substantial influence on ecological function and processes.

The IUCN’s list is considered the authoritative, albeit likely conservative, assessment of the conservation status of plant and animal species. About 1.8 million species have been described since 1758 (when the current nomenclature system was developed), of which 1.3 million are animals (3, 17). Of these animal species, about 39,223 (of the currently counted 66,178) vertebrate species have been formally assessed and reported in the 2014 IUCN Red List (17). In the IUCN sample, mammals, birds, and amphibians have had between 88 and 100% of their known species evaluated, whereas only 44% of reptiles and 38% of fish species have been assessed (Table 1). We focus our comparisons on vertebrates because they are the group for which the most reliable data exist, both fossil and modern.

To produce conservative comparisons with modern extinctions, we assumed a background extinction rate of 2 E/MSY as the highest likely baseline average background extinction rate (7); that is, we should expect 2 extinctions per 10,000 vertebrate species per 100 years. That background extinction rate was empirically determined using the exceptionally good fossil records of mammals, combining extinction counts from paleontological databases and published literature on the fossil, subfossil, and historical records (7). Using the resulting high background extinction rate provides a stringent test for assessing whether current modern extinction rates indicate that a mass extinction event is under way. Previous estimates of background extinction rates for other taxa are invariably lower than the mammal-derived estimate of 2 E/MSY used here.

SUPPLEMENTARY MATERIALS

Table S1. Definitions of IUCN categories (17) used to assess modern extinction rates.

Table S2. Estimation of modern extinction rates since 1500 and 1900.

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.

Acknowledgments: We would like to thank B. Young for helping us with the data on “possibly extinct species” published by IUCN. J. Soberon, C. Mendenhall, and J. Pacheco gave valuable suggestions on the manuscript. Funding: This work has been supported by the Programa de apoyo a proyectos de investigación e innovación tecnológica from UNAM. Competing interests: The authors declare that they have no competing interests.